For a quick slope check, yes the explore object or smart text works better and is more applicable.

I see the profile view option having more value of getting the overall picture of slopes along the profile. More of a design tool. What slope are you going into/out of? Explore object only gives you the instantaneous slope at that point of the line so if you are. Something such as a ditch with varying slopes would be a good case for this.

It would be a great help If we could see in the properties or even better in the edit linestring, when you put in the Z value and push tab to see the slope and the distance of the line, so you can make some changes before saving the value, open the explore object and click on the segment to know its properties, or to go in the tab vertical and figure out wich segment it is to see it's slope go back to the horizontal tab, find the segment and change value.

Maybe it is my problem because I work on smaller project, where creating a corridor is'nt an option.